Call buyers find Micron in the chips

optionMONSTER's Heat Seeker system detected heavy buying in the May 10 calls, which traded in big chunks for $0.42. More than 22,000 of the contracts traded against open interest of 2,411, so these are new positions.

Those calls lock in the price where investors can buy the stock, so they can generate some nice leverage in the event of a rally. But if the shares don't move, these contracts could lose all their value.(See our Education section)

MU fell 2.58 percent to $9.07 in regular trading yesterday. Its options have very active recently, and the memory-chip maker's shares have already shot up 43 percent so far this year.

The company reported second-quarter revenue of $2.08 billion after the bell. That beat the $1.92 billion expected by analysts, and the stock added another 3.4 percent in extended hours.

Calls outpaced puts by almost 135,000 to 44,000 in the session. Total option volume was 5 times greater than average.